Iida Municipal Hospital is a regional acute care facility with approximately 407 beds, providing tertiary emergency services. However, the hospital faces challenges such as a shortage of physicians, particularly surgeons, and an aging population. To address these issues and promote work-style reform, we introduced a clinical engineer-led scope operator service for thoracic surgery in April 2023. Following approval from the hospital's ethics committee, clinical engineers received dry lab training and observed surgeries before participating in actual procedures. A total of 253 thoracoscopic surgeries performed between January 2021 and December 2024 were retrospectively divided into two groups: one with clinical engineers serving as scope operators, and one with assistant surgeons serving in the same role. We evaluated the safety of both groups. The findings indicated that involving clinical engineers as scope operators was beneficial not only for surgeons, but also for the hospital as a whole, contributing to improved work practices and efficiency.

We conducted a retrospective analysis of 8 patients who underwent local treatment, including surgical resections and radiotherapy, for local recurrence or second primary lung cancer in the residual lobe after segmentectomy, among 375 patients who had undergone segmentectomy for primary non-small cell lung cancer at our institution between 2008 and 2022. The median interval from initial segmentectomy to local treatment was 57 months. Local treatments consisted of completion lobectomy in 4 patients, another segmentectomy in 1, and stereotactic body radiotherapy (SBRT) in 3. Surgical procedures were performed safely, without perioperative mortality or severe complications. In patients who underwent surgical resection, pathological examination revealed local recurrence in 3 patients and second primary lung cancer in 2. SBRT was selected for 2 patients with comorbidities and a poor performance status, and for 1 patient with a history of prior pulmonary resection for multiple lung cancers. The median follow-up after local treatment was 29 months, during which 2 patients died (1 from lung cancer, and 1 from another malignancy). Local treatment for residual lobe lesions after segmentectomy demonstrated favorable clinical outcomes. Surgery was safely performed without severe complications, and SBRT yielded favorable outcomes and may represent a viable treatment option.

Background: High-grade fetal adenocarcinoma (H-FLAC) is a rare type of lung cancer that has been reported to be associated with a poor prognosis. However, its clinical and pathological characteristics remain insufficiently understood.

Methods・Purpose: We retrospectively analyzed 10 patients with lung cancer including H-FLAC or those containing H-FLAC components who underwent radical resection at our institution between January 2015 and March 2025.

Results: The cohort included 8 men and 2 women. The mean age was 67 years. Proportions of the H-FLAC component were: 1-9% in 3 patients, 10-50% in 4, and greater than 50% in 3. Pathological stages were: stage I in 5 patients, stage II in 3, and stage III in 2. Lymphovascular invasion was observed in 7 patients, pleural invasion in 4, and spread through air spaces in 6. The median follow-up period was 47 months. Postoperative adjuvant therapy tailored to the mixed histological components was administered to four patients. Recurrence occurred in three; however, individualized treatments were provided based on the mixed components, sites of recurrence, and re-biopsy findings, and all patients remained alive at the time of analysis.

Conclusion: In patients with lung cancer containing H-FLAC components, selecting therapeutic strategies that account for their heterogeneous histology may lead to improved prognoses.

An anomalous unilateral single pulmonary vein (AUSPV) is a rare pulmonary venous anomaly in which a part of the unilateral pulmonary vein is disconnected from the left atrium. In this condition, the dilated and tortuous peripheral pulmonary vein joins the remaining ipsilateral pulmonary vein and enters the left atrium. Although AUSPV is extremely rare and imaging findings are similar to those of pulmonary arteriovenous fistulas, understanding its presence and accurate imaging can help avoid unnecessary invasive tests and procedures.

In this study, we encountered two cases of asymptomatic AUSPV that were discovered incidentally. When abnormal pulmonary vessels are detected, vascular rundown must be checked for, not only at the site of abnormality but also along the entire course of vessels.

A 70-year-old man visited the hospital because of numbness in his limbs, which had appeared and worsened over the course of one month. Myokymia was observed in his limbs and trunk without muscle weakness, and excessive sweating and constipation were also noted. Needle electromyography identified myokymia discharges, and blood examination showed positive results for anti-LGI1 and anti-CASPR2 antibodies. Chest computed tomography revealed an anterior mediastinal tumor, and he was diagnosed with thymoma plus Isaacs syndrome. After the symptoms of Isaacs syndrome were stabilized with plasma exchange, he underwent thoracoscopic extended thymectomy. After surgery, intravenous immunoglobulin therapy, plasma exchange, and oral prednisolone therapy were performed, and his symptoms gradually improved until only slight numbness remained in his hands and feet.

Micronodular thymic carcinoma with lymphoid hyperplasia (MNCLH) is a rare disease classified as a subtype of thymic squamous cell carcinoma, according to the WHO classification 5th edition. A 61-year-old man presented with an anterior mediastinal tumor on chest computed tomography. Robot-assisted thymectomy was performed, and thymoma was suspected. Pathological examination revealed tumor cells with mild atypia separated by abundant lymphoid stroma into small nodules. Immunohistochemistry revealed that the tumor cells were positive for: AE1/AE3, p40, CK5/6, p63, CD5, and CD117 (C-kit). In addition, immature TdT-positive T cells were absent from the background of tumor cells, supporting the diagnosis of MNCLH. The patient survived and has been recurrence-free for 11 months since surgery without adjuvant therapy.

The patient was a 29-year-old woman who, after traveling to Central and South America, was found to have multiple bilateral pulmonary nodules on a routine chest radiograph. Chest computed tomography (CT) revealed multiple well-defined small nodules, up to 1.5 cm in diameter, scattered in both lungs. Because metastatic lung tumors could not be ruled out, a thoracoscopic partial resection of the left upper lobe was performed for diagnostic purposes. The resected specimen measured approximately 0.5 cm and appeared yellowish in color. Histological examination revealed caseous necrosis-like changes in the central area, with peripheral granulomatous inflammation composed of epithelioid cells. Both acid-fast staining and periodic acid-Schiff (PAS) staining were negative. However, Grocott's methenamine silver stain demonstrated scattered round to oval yeast-like organisms. Polymerase chain reaction (PCR) identified a product specific for Histoplasma capsulatum, leading to a diagnosis of pulmonary histoplasmosis. The patient was immunocompetent and remained asymptomatic. In accordance with the Infectious Diseases Society of America (IDSA) guidelines, a strategy of observation without antifungal therapy was adopted. The patient returned to the UK postoperatively and has been followed with imaging studies, showing no evidence of recurrence to date.

In certain cases, pulmonary histoplasmosis is considered to represent a pulmonary malignancy, for which thoracic surgeons may perform a biopsy. Several important clinical considerations should therefore be taken into account.

The patient was a man in his 70s. He was diagnosed with right upper lobe lung adenocarcinoma and suspected simultaneous right lower lobe lung cancer following a physical examination. He underwent thoracoscopic right upper lobectomy and wedge resection of right lower lobe resection and mediastinal lymph node dissection. During surgery, we ligated and closed the middle lobe using ENDOLOOP™ Ligature where air leakage occurred after interlobar fissure resection between the upper and middle lobes using an autosuture device. On the day after surgery, the patient suddenly lost consciousness and became hypotensive. As echocardiography revealed cardiac tamponade, we performed emergency surgery with median sternotomy. Two puncture holes were found in the pericardium adjacent to the bleeding point. After right pleural incision, we found that the ENDOLOOP™ Ligature stump in the middle lobe adjacent to pericardium was sharp and pointed. We considered that it had penetrated the pericardium and aorta.

A 31-year-old woman was referred to our hospital 8 years previously because of an abnormal shadow detected on a chest radiograph during an annual medical check-up. Chest computed tomography revealed a well-demarcated and smooth-margined tumorous lesion measuring 0.6 cm in the apical segment of the left upper lobe. The size of the lesion had gradually increased over a period of 8 years, reaching a diameter of 1.4 cm. From the radiological findings, we suspected the tumor to be either a pulmonary hamartoma with minimal calcification or sclerosing pneumocytoma. Pulmonary wedge resection by video-assisted thoracoscopic surgery was performed for diagnosis and treatment. Histopathological findings showed fascicular proliferation of tumor cells with eosinophilic cytoplasm and short spindle-shaped nuclei along with a perivascular growth pattern. The tumor cells were immunohistochemically positive for smooth muscle actin and h-caldesmon and negative for desmin. On the basis of histopathological examinations and clinical findings, including the absence of other lesions, the tumor was diagnosed as primary pulmonary myopericytic neoplasm. Myopericytic neoplasm of the lung is extremely rare, and prior to this instance, no cases in Japan had been reported. We also reviewed and discussed the published case reports of primary pulmonary myopericytoma.

A male in his eighties presented with nausea and vomiting, and imaging revealed a 12-cm mass located anterior to and markedly compressing the heart. The tumor showed smooth margins and homogeneous enhancement on abdominal CT, and PET-CT demonstrated uniform FDG uptake with an SUVmax of 16.9. Laboratory tests revealed mildly elevated LDH and soluble IL-2 receptor levels, suggesting malignant lymphoma. Nevertheless, due to concerns regarding possible tumor seeding from needle biopsy, as well as the risks of worsening cardiac compression or circulatory collapse during the procedure, surgical resection was selected for both diagnostic and therapeutic purposes. After thoracoscopic dissection of the tumor from the right thoracic cavity, left thoracotomy was performed; however, visualization was inadequate, prompting the addition of transverse sternotomy, which enabled safe tumor removal through a semi-clamshell approach. Postoperative pathological examination confirmed diffuse large B-cell lymphoma, and R-CHOP therapy was initiated. This case underscores important diagnostic considerations, as surgical resection was chosen despite preoperative findings suggestive of lymphoma, highlighting the need for careful preoperative evaluation and multidisciplinary collaboration when managing patients with giant mediastinal tumors.

An 82-year-old woman was incidentally found to have a 22-mm cavitary nodule in the peripheral segment S⁸ of the left lung on chest computed tomography. The lesion was considered primary lung cancer in the left lower lobe (cT1cN0M0, c-Stage IA3). Robot-assisted left lower lobectomy with lymph node dissection (ND2a-1) was performed. The tumor appeared as a brownish nodule, and histopathological examination revealed eosinophilic deposits accompanied by giant cell infiltration, mild fibrosis, and ossification. The eosinophilic deposits were positive on direct fast scarlet staining, and the staining persisted after permanganate treatment, supporting a pathological diagnosis of nodular pulmonary amyloidosis. Conversely, small to medium sized lymphocytes and plasma cells showed dense infiltration around the nodule. Immunohistochemically, the infiltrating cells were positive for CD20 and focally positive for CD43. Furthermore, immunoglobulin light chain analysis showed light chain restriction with λ-chain predominance. Based on these findings, the tumor was diagnosed as primary pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma with nodular pulmonary amyloidosis.

A 56-year-old man was incidentally found to have multiple anterior mediastinal tumors during follow-up for an abdominal aortic aneurysm detected during a health checkup. Chest CT revealed multiple small nodules surrounding the main lesion, raising the suspicion of thymoma. A bilateral thoracoscopic total thymectomy was performed for both diagnostic and therapeutic purposes. Histopathological examination revealed cholesterol clefts surrounded by foreign body-type multinucleated giant cells, foamy macrophages, and lymphocytes, leading to a diagnosis of cholesterol granuloma. Although it is rare, cholesterol granuloma should be considered as a differential diagnosis when vascular disease or dyslipidemia is present, or when scattered small nodules are observed on imaging. When malignancy, such as a thymic epithelial tumor, cannot be excluded preoperatively, intraoperative frozen section diagnosis may help determine whether limited resection is appropriate.

Recently, perioperative treatment of lung cancer with immune checkpoint inhibitors (ICIs) has attracted attention, and the number of patients undergoing surgery after ICI therapy is expected to rise. We report a case of intraoperative pulmonary artery bleeding due to failed staple formation of the truncus superior of the right pulmonary artery after treatment with ICIs. A man in his 70s was diagnosed with cT2aN1M0-stage IIB squamous cell carcinoma of the right upper lobe. Because he was considered unsuitable for pneumonectomy or definitive chemoradiotherapy, pembrolizumab monotherapy was administered for three cycles. The tumor, however, enlarged and the response to pembrolizumab was categorized as progressive disease. At the patient's request, he was referred to our department. Computed tomography revealed a 3.6-cm mass in the right upper lobe, and bronchoscopy showed tumor-related bleeding obstructing the upper lobe bronchus. The patient was re-evaluated to be in the ycT2aN1M0-stage IIB, and surgery was indicated because of hemoptysis and airway obstruction. During transection of the truncus superior, stapling failure led to massive bleeding from the proximal stump. Hemostasis was achieved by conversion to an intrapericardial approach, with proximal control of the right main pulmonary artery followed by repair of the dehisced stapling line. The tumor invading the second carina of the upper lobe bronchus was excised via right upper sleeve lobectomy. The patient had no complications and was discharged on postoperative day 18.

This case suggests that perivascular fibrosis after ICI treatment may increase the risk of stapling failure. In patients with severe hilar fibrosis after ICI therapy, surgeons should anticipate the risk of pulmonary artery injury and consider early intrapericardial exposure of the main pulmonary artery before hilar manipulation. Mastery of intrapericardial control of the right main pulmonary artery is essential for safely managing potentially life-threatening bleeding from the truncus superior.

During chemotherapy for acute myeloid leukemia (AML), patients are in a state of marked immunosuppression and susceptible to fungal infections. Surgical resection is the optimal treatment for simple pulmonary aspergilloma (SPA). To avoid postoperative complications, temporary cessation of chemotherapy during the perioperative period is necessary; however, the interruption should be minimized to preserve the curative potential for AML. We describe a 15-year-old female undergoing induction chemotherapy for AML. On day 11 of the first induction cycle, she developed persistent fever, for which broad-spectrum antibiotics were initiated. Chest computed tomography on day 22 demonstrated SPA in the left S¹⁺² segment because the fever continued. Subsequently, antifungal therapy was started. The second induction cycle was administered on day 43, and left S¹⁺² segmentectomy was performed on day 68. Subsequently, three courses of consolidation chemotherapy were completed without complication. Six months after the completion of therapy, there was no recurrence of SPA, the patient achieved remission from AML, and returned to school. This case is notable because surgical resection of SPA during ongoing AML chemotherapy in an adolescent has rarely been documented. With a carefully coordinated multidisciplinary strategy, both SPA and AML were successfully controlled, resulting in a favorable clinical outcome.